1 files changed, 151 insertions, 0 deletions
diff --git a/gitstatus/src/string_cmp.h b/gitstatus/src/string_cmp.h
new file mode 100644
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+++ b/gitstatus/src/string_cmp.h
@@ -0,0 +1,151 @@
+// Copyright 2019 Roman Perepelitsa.
+//
+// This file is part of GitStatus.
+//
+// GitStatus is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GitStatus is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GitStatus. If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef ROMKATV_GITSTATUS_STRING_CMP_H_
+#define ROMKATV_GITSTATUS_STRING_CMP_H_
+
+#include <string.h>  // because there is no std::strcasecmp in C++
+
+#include <algorithm>
+#include <cctype>
+#include <cstddef>
+#include <cstring>
+
+#include "string_view.h"
+
+namespace gitstatus {
+
+// WARNING: These routines assume no embedded null characters in StringView. Violations cause UB.
+
+template <int kCaseSensitive = -1>
+struct StrCmp;
+
+template <>
+struct StrCmp<0> {
+  int operator()(StringView x, StringView y) const {
+    size_t n = std::min(x.len, y.len);
+    int cmp = strncasecmp(x.ptr, y.ptr, n);
+    if (cmp) return cmp;
+    return static_cast<ssize_t>(x.len) - static_cast<ssize_t>(y.len);
+  }
+
+  int operator()(StringView x, const char* y) const {
+    for (const char *p = x.ptr, *e = p + x.len; p != e; ++p, ++y) {
+      if (int cmp = std::tolower(*p) - std::tolower(*y)) return cmp;
+    }
+    return 0 - *y;
+  }
+
+  int operator()(char x, char y) const { return std::tolower(x) - std::tolower(y); }
+  int operator()(const char* x, const char* y) const { return strcasecmp(x, y); }
+  int operator()(const char* x, StringView y) const { return -operator()(y, x); }
+};
+
+template <>
+struct StrCmp<1> {
+  int operator()(StringView x, StringView y) const {
+    size_t n = std::min(x.len, y.len);
+    int cmp = std::memcmp(x.ptr, y.ptr, n);
+    if (cmp) return cmp;
+    return static_cast<ssize_t>(x.len) - static_cast<ssize_t>(y.len);
+  }
+
+  int operator()(StringView x, const char* y) const {
+    for (const char *p = x.ptr, *e = p + x.len; p != e; ++p, ++y) {
+      if (int cmp = *p - *y) return cmp;
+    }
+    return 0 - *y;
+  }
+
+  int operator()(char x, char y) const { return x - y; }
+  int operator()(const char* x, const char* y) const { return std::strcmp(x, y); }
+  int operator()(const char* x, StringView y) const { return -operator()(y, x); }
+};
+
+template <>
+struct StrCmp<-1> {
+  explicit StrCmp(bool case_sensitive) : case_sensitive(case_sensitive) {}
+
+  template <class X, class Y>
+  int operator()(const X& x, const Y& y) const {
+    return case_sensitive ? StrCmp<1>()(x, y) : StrCmp<0>()(x, y);
+  }
+
+  bool case_sensitive;
+};
+
+template <int kCaseSensitive = -1>
+struct StrLt : private StrCmp<kCaseSensitive> {
+  using StrCmp<kCaseSensitive>::StrCmp;
+
+  template <class X, class Y>
+  bool operator()(const X& x, const Y& y) const {
+    return StrCmp<kCaseSensitive>::operator()(x, y) < 0;
+  }
+};
+
+template <int kCaseSensitive = -1>
+struct StrEq : private StrCmp<kCaseSensitive> {
+  using StrCmp<kCaseSensitive>::StrCmp;
+
+  template <class X, class Y>
+  bool operator()(const X& x, const Y& y) const {
+    return StrCmp<kCaseSensitive>::operator()(x, y) == 0;
+  }
+
+  bool operator()(const StringView& x, const StringView& y) const {
+    return x.len == y.len && StrCmp<kCaseSensitive>::operator()(x, y) == 0;
+  }
+};
+
+template <int kCaseSensitive = -1>
+struct Str {
+  static_assert(kCaseSensitive == 0 || kCaseSensitive == 1, "");
+
+  static const bool case_sensitive = kCaseSensitive;
+
+  StrCmp<kCaseSensitive> Cmp;
+  StrLt<kCaseSensitive> Lt;
+  StrEq<kCaseSensitive> Eq;
+};
+
+template <int kCaseSensitive>
+const bool Str<kCaseSensitive>::case_sensitive;
+
+template <>
+struct Str<-1> {
+  explicit Str(bool case_sensitive)
+      : case_sensitive(case_sensitive),
+        Cmp(case_sensitive),
+        Lt(case_sensitive),
+        Eq(case_sensitive) {}
+
+  bool case_sensitive;
+
+  StrCmp<-1> Cmp;
+  StrLt<-1> Lt;
+  StrEq<-1> Eq;
+};
+
+template <class Iter>
+void StrSort(Iter begin, Iter end, bool case_sensitive) {
+  case_sensitive ? std::sort(begin, end, StrLt<true>()) : std::sort(begin, end, StrLt<false>());
+}
+
+}  // namespace gitstatus
+
+#endif  // ROMKATV_GITSTATUS_STRING_CMP_H_